JP2014530993A - Peristaltic pump and pump head for peristaltic pump - Google Patents

Abstract

A peristaltic type including a pump chamber (16) in which a pressing element (48) that gives a peristaltic action to a tube (52) extending therein is disposed, and an auxiliary chamber (18) that is a drying chamber in normal use. Pump head (2). In the pump chamber (16) and the auxiliary chamber (18), the liquid moved from the pump chamber (16) due to leakage from the tube (52) to the pump chamber (16) is transferred from the pump chamber (16) to the auxiliary chamber (18). Arranged in fluid communication to flow. [Selection] Figure 2

Description

  The present invention relates to a peristaltic pump and a pump head for a peristaltic pump.

  Peristaltic pumps are commonly used in applications where it is not desirable for the fluid being pumped to contact the components of the pump. For example, peristaltic pumps are frequently used to pump sterilized or abrasive fluids that can be contaminated or damaged by contact with components inside the pump. For this reason, peristaltic pumps are frequently used in the beverage industry where a sterile pumping process is required and in the aggregate industry where a slurry containing abrasive particles needs to be carried.

  Peristaltic pumps generally include a pump housing in which the tube extends and a pressing element disposed within the pump housing to provide peristaltic action to the tube. The pressing element typically has one or more rotors or “wipers” that are moved along the tube to provide a peristaltic action.

  Normally, it is desirable to replace the tube before it fails, but in some situations it is possible that the tube will rupture inside the pump head housing and the pumped fluid will leak into the housing. In many cases, the housing is provided with an outlet through which leaked fluid is discharged. This prevents excessive accumulation of fluid in the housing.

  It is desirable to provide a lubricating fluid in the pump housing to reduce the amount of tube and roller wear. In order to prevent the lubricating fluid from being discharged from the housing, the outlet is often provided with a valve. The valve is configured to be closed in normal use and open only when a leak occurs. A problem associated with such a configuration is that when a leak is detected within a housing and a normally closed valve is detected, as described in US Pat. No. 7,001,153. It requires a complicated system to open. Furthermore, the use of a valve that is normally closed but must be opened when a leak is detected means that failure to open the valve can cause an excessive increase in fluid within the housing.

  According to the first aspect of the present invention, the peristaltic type includes a pump chamber in which a pressing element that gives a peristaltic motion to a tube extending inside is disposed, and an auxiliary chamber that is a drying chamber in normal use. A pump head, wherein the pump chamber and the auxiliary chamber are in fluid communication such that liquid that is moved from the pump chamber due to leakage from the tube to the pump chamber flows from the pump chamber to the auxiliary chamber. A peristaltic pump head is provided which is arranged in the above state.

  The liquid moved from the pump chamber can be configured to be lubricating oil that exists in the pump chamber in normal use and is discharged from the pump chamber by the pumped fluid leaking from the tube. In addition, the leaked fluid can be configured to be moved from the pump chamber to the auxiliary chamber.

  The auxiliary chamber is a valve operable between an open state in which liquid can flow from the pump chamber to the auxiliary chamber and a closed state in which liquid does not flow from the pump chamber to the auxiliary chamber. It can comprise so that it may communicate with the said pump chamber via.

  The valve may be configured such that when the pump head is connected to a drive unit that drives the pressing element, the drive unit engages the pump head to open the valve.

  The valve can be configured to include a port and a piston that engages the port to close the port. The valve may be configured to include a biasing element that biases the valve to the closed state.

  A liquid detector for detecting the presence of liquid in the auxiliary chamber may be arranged.

  The auxiliary chamber may be provided with an outlet. The outlet includes a snorkel, and the snorkel defines a container for containing liquid below the inlet of the snorkel when the pump head is attached to a drive unit that drives the pump head. The fluid detector can be arranged to detect the presence of a liquid in the container.

  According to a second aspect of the present invention, there is provided a peristaltic pump including a pump head according to the first aspect of the present invention and a drive unit, wherein the pump head is configured to be detachable from the drive unit. A peristaltic pump is provided.

  In an embodiment of the pump head including a valve that provides communication between the auxiliary chamber and the pump chamber, the pump head includes a plunger that drives a valve exposed to the outside of the pump head, and The drive unit may be configured with a protrusion that cooperates with the plunger to open the valve when the pump head is attached to the drive unit.

  According to a third aspect of the present invention, there is provided a peristaltic pump head including a pump head housing having a substantially cylindrical outer wall and at least one end cap permanently fixed to the outer wall. Is done. The end cap can be configured to be spin welded or ultrasonically staked to the outer wall to form a sealed pump head housing. The outer wall that is spin welded to the end cap or ultrasonically stake can be configured to have a mold structure.

  To facilitate an understanding of the present invention and to clarify how it can be implemented, the accompanying drawings are referred to by way of example.

It is a perspective view of the pump head for a peristaltic pump. It is a cross-sectional perspective view of the pump head shown in FIG. It is sectional drawing of the pump head shown by FIG. FIG. 3 is another cross-sectional view of the pump head shown in FIG. 1, showing the pump head disposed on the emitter and receiver. FIG. 4 is an enlarged partial cross-sectional view of the pump head corresponding to the cross-sectional view shown in FIG. 3, showing the pump head in a state where a valve in the pump head is closed. FIG. 6 is a view corresponding to FIG. 5 and showing the pump head in a state where the valve is opened. It is sectional drawing along the VII line of the pump head shown by FIG. FIG. 5 is another cross-sectional view along the line VIII of the pump head shown in FIG. 3. FIG. 3 is a cross-sectional perspective view of another embodiment of the pump head shown in FIG. 1. FIG. 10 is a cross-sectional view of the pump head shown in FIG. 9. FIG. 10 is an enlarged view of the vicinity of the valve of the pump head shown in FIG. 9, showing the pump head in a state where the valve is closed. It is a figure corresponding to FIG. 11, Comprising: It is a figure which shows the pump head of the state in which the valve | bulb was opened.

  1 and 2 show a pump head 2 used in a peristaltic pump. The pump head 2 has a substantially cylindrical outer wall 6 closed at both ends by end caps 8 and 10, any one or all of the end caps 8 and 10 being of suitable thermoplastic properties. Can be made from plastic. Either one or both of the outer wall 6 and / or the end cap can be manufactured by molding. In order to form a sealed housing 4, the end caps 8 and 10 are spin welded to the outer wall 6 or ultrasonically struck to the outer wall 6. A cylindrical outer wall 6 of the housing 4 defines the axis of the pump head. The end cap 10 is arranged on the drive unit 1 to ensure that the pump head 2 is arranged in one of a plurality of predetermined directions with respect to the drive unit 1 (partially shown in FIG. 6). A positioning recess 11 is disposed in the protrusion.

  As shown in FIG. 2, the housing 4 is divided into a pump chamber 16 and an auxiliary chamber 18 by a substantially cylindrical inner wall 12 and an inner end wall 14. The inner walls 12 and 14 are constituted by a spar 20 extending in the axial direction and the radial direction, and a circumferential rib 22 extending in a direction perpendicular to the inner and outer cylindrical walls 6 and 12. The outer wall 6 is supported. The inner wall 12 and the outer wall 6 have an annular passageway 24 extending between an annular slot 26 defined between the inner wall 12 and the end cap 8 and a circumferential rib 22. Determine. The annular slot 26 provides fluid communication between the pump chamber 16 and the passage 24.

  The auxiliary chamber 18 is coaxial with the pump chamber 16. As shown in FIG. 3, the auxiliary chamber 18 includes an annular region 28 extending around the pump chamber 16 and a substantially cylindrical collection region 30 defined approximately between the end cap 10 and the inner wall 14. ,including.

  A valve 32 is disposed between the pump chamber 16 and the auxiliary chamber 18. The valve 32 has a port 34 in the circumferential rib 22 and a piston 36 that can be moved into sealing engagement with the port 34 to open or close the valve 32, or otherwise. Including. The piston 36 is connected to a plunger 38 that extends from the piston 36 through the end cap 10 that defines the auxiliary chamber 18 so as to protrude from the housing 4. The end of the plunger 38 protruding from the housing 4 has a pressing feature 40, such as a button, which can be pressed to actuate the plunger 38, Moves the piston 36 into a sealed and disengaged state with the port 34 and opens the valve 32. The pressing mechanism 40 is disposed in a recess 42 provided in the end cap 10. The pressing mechanism 40 and the recess 42 are configured such that the pressing mechanism 40 is flush with the main part of the end cap 10 when the valve 32 is closed.

  The auxiliary chamber 18 is provided with an outlet. The outlet includes a pipe 44 that extends through the outer wall 6 and projects into the lower region of the auxiliary chamber 18. As shown in FIG. 3, a part of the pipe 44 in the auxiliary chamber 18 is provided with a snorkel 45 extending to the auxiliary chamber 18, and the pipe 44 is provided when the pump head 2 is in a predetermined operation direction. A snorkel inlet 47 is disposed in the auxiliary chamber 18 above the lowermost portion of the auxiliary chamber 18. The area surrounding the snorkel 45 in the auxiliary chamber 18 defines a container portion in the periphery of the snorkel 45 for storing liquid when the snorkel 45 is in an upright state. A plug to which a hose can be connected is provided on a part of the pipe 44 extending to the outside of the pump head 2 in a direction away from the outer wall 6.

  A rotor 46 extends through the end cap 10, the end wall 14 and the pump chamber 16 along the axis of the pump head. The rotor 46 is supported in the pump head 2 by a bearing. A part of the rotor 46 protruding from the pump head 2 can be connected to the drive unit 1 that drives the rotor 46. A portion of the end cap 10 and a portion of the end wall 14 through which the rotor 46 extends extend are adjacent to each other in the axis of the pump head. As a result, the rotor 46 is not exposed to the auxiliary chamber 18. A pressing element 48 is arranged inside the pump chamber 16. The pressing element 48 is coupled to the rotor 46 for rotation. The pressing element 48 has a protrusion 50 (shown more clearly in FIG. 7) arranged to press the tube 52 adjacent to the pressing element 48 against the inner wall 12. Therefore, the inner wall 12 includes a pressing surface that separates the pump chamber 16 from the auxiliary chamber 18 and presses the tube 52.

  As shown in FIG. 4, the pump head 2 further includes a reflector 53 arranged in the region of the container portion in the auxiliary chamber 18. The reflector 53 includes a cone portion made of a material that is substantially transparent to infrared light, although electromagnetic radiation of other wavelengths may be used. The reflector 53 can be made of, for example, polysulfone or other suitable material. The reflector 53 is arranged so that the cone portion is converged from the end cap 10 into the auxiliary chamber 18 and the base portion of the cone is exposed to the outside of the pump head 2. The reflector 53 can be formed integrally with the end cap 10.

  When the container portion of the auxiliary chamber 18 is not wet, the conical surface of the cone portion 53 is exposed to air. Under this condition, infrared light that passes through the base portion and travels parallel to the axis of the cone portion is reflected inside the conical surface of the cone portion so as to return to the base portion. In the present embodiment, the reflector 53, and particularly the apex angle thereof, is such that when the cone portion is exposed to the liquid, the interface between the cone portion and the liquid does not reflect infrared light and returns through the base portion. It is comprised so that intensity | strength may decrease according to the grade by which the cone part is flooded.

  As shown in FIGS. 7 and 8, the pump chamber 16 has a first port 54 and a second port 56 provided in the inner wall 12. The first passage 58 and the second passage 60 extend from the ports 54 and 56 toward the openings 62 and 64 provided in the bosses 66 and 68 formed in the outer wall 6, respectively. The passages 58 and 60 include a direct communication between the pump chamber 16 and the openings 62 and 64 of the outer wall 6. The passages 58 and 60 extend in substantially opposite directions in the tangential direction of the housing 6.

  The bosses 66 and 68 are provided with recesses 63 and 65. Each of the recesses 63 and 65 extends around each of the openings 62 and 64.

  The tube 52 passes through the pump chamber 16 along the first passage 58 from the first opening 62 and extends from the pump chamber 16 to the second opening 64 along the second passage 60. The tube 52 is annularly disposed around the rotor 46 so as to be disposed between the pressing element 48 and the inner wall 12.

  Tube end connectors 70 and 72 are disposed in the openings 62 and 64. Each of the end fittings 70 and 72 includes a through passage 74 and 76 extending axially relative to the end fittings 70 and 72, adjacent shoulders 78 and 80 in the form of flanges, and adjacent shoulders. Male threaded shanks 82 and 84 extending in a direction away from 78 and 80. Screw shanks 82 and 84 taper in a direction away from adjacent shoulders 78 and 80. Plugs 83 and 85 are provided at the ends of the connectors 70 and 72 opposite to the screw shanks 82 and 84. A hose (not shown) can be connected to the plugs 83 and 85.

  Each of the end fittings 70 and 72 has an adjacent shoulder 78 and 80 adjacent one of the bosses 66 and 68 formed in the outer wall 6, and screw shanks 82 and 84 along the passages 58 and 60. Are arranged so as to extend toward the pump chamber 16. Screw shanks 82 and 84 extend into the end of tube 52 such that the screws engage the inner wall of tube 52. The outer diameter of the screw shanks 82 and 84 adjacent to the adjacent shoulders 78 and 80 is such that the shanks 82 and 84 secure the tube 52 between the connectors 70 and 72 and the housing 4 to the inner walls of the passages 58 and 60. The size can be coordinated. Adjacent shoulders 78 and 80 and corresponding recesses 63 and 65 around the openings 62 and 64 define circumferentially extending slots 86 and 88 that receive the ends of the tube 52.

  A holding element composed of elastic caps 90 and 92 is arranged so as to cover the end of each of the connectors 70 and 72. Each of caps 90 and 92 has openings 94 and 96 at the ends of caps 90 and 92 through which plugs 83 and 85 extend. Around the sides of the caps 90 and 92, other openings 98 and 100 are circumferentially spaced apart. The openings 98 and 100 engage corresponding protrusions 102 and 104 provided on a portion of the housing 4 adjacent to the openings 62 and 64.

  The assembly of the tube 52 in the pump head 2 is as follows.

  The end of the tube 52 passes through the first opening 62 and the first passage 58 and is inserted into the housing 4 and is pushed into the pump chamber 16. The end portion of the tube 52 is in contact with the inner wall 12 between the protruding portion 50 of the pressing element 48 and the inner wall 12, and slides around the rotor 46 along the inner surface of the inner wall 12. Pass through the passage 60 and the second opening 64 and exit the pump chamber 16. The tube 52 may include a lead portion (not shown) having an outer diameter smaller than the clearance between the protrusion 50 and the inner wall 12. The smaller diameter portion facilitates passing the lead through the housing. If the lead portion of the tube 52 passes through the housing 4, the main portion of the tube 52 can be pulled by pulling at the lead portion. When the main part of the tube 52 is properly positioned, the lead can be cut from the tube 52. The tube 52 can also be passed through the housing 4 in the opposite direction by inserting the end of the tube 52 into the second opening 64.

  The length of the tube 52 inside the housing 4 must be sized to ensure proper operation of the pump head. The tube 52 has a length that allows the tube 52 to be properly positioned within the pump chamber 16 when the end of the tube 52 is positioned in the openings 62 and 64. When tube 52 is pulled from the pump head, one or both of the ends of tube 52 will not be properly placed in openings 62 and 64. For example, the end of the tube that is initially inserted into the pump head 2 may be the second (for example, because the person who assembles the pump head cannot exert sufficient force to pull the tube past the housing 4). A part may be pulled out through the two passages 60.

  The screw shank 84 of the connection tool 72 disposed in the second opening 64 passes through the second opening 64 and is inserted into the end of the tube 52. The screw engages with the inner wall of the tube 52. The adjacent shoulder 80 pushes the connector 72 into the housing 4 or against the tube 52 so that the threaded engagement between the tube 52 and the connector 72 further pulls the screw shank 84 toward the tube 52. The connector 72 is engaged with the boss 68 of the housing 4 by rotating the connector 72. When the adjacent shoulder 80 is adjacent to the boss 68, the boss 68 prevents the connector 72 from being pulled further toward the housing 4. The connector 72 is then rotated relative to the tube 52 or relative to the tube 52 to pull the end of the tube 52 along the screw shank 84 toward the adjacent shoulder 80 and the opening 64. It is further rotated. As the tube 52 is pulled toward the adjacent shoulder 80, the tube 52 is compressed between the shank 84 and the inner wall of the passage 60. When the end of the tube 52 is adjacent to the adjacent shoulder 80, further rotation of the connector 72 relative to the housing 4 pushes the end of the tube 52 into a circumferential slot 88 defined between the adjacent shoulder 80 and the recess 65 of the housing 4. . As a result, the end of the tube 52 is firmly fixed at the correct position in the second opening 64.

  The cap 92 is disposed so as to cover the connector 72 so that the stopper 85 passes through the opening 96 at the end of the cap 92. A force is applied to the cap 92 so as to spread the cap 92 and press the cap 92 against the flange forming the adjacent shoulder 80. When the opening 100 is aligned with the protrusion 104, the protrusion 104 enters the opening and secures the cap 92 to the housing 4 as well as the cap 92 to secure the flange and consequently the connector 72 to the housing 4. Returns to its original shape. As a result, the cap 92 is snap-fitted to the housing 4.

  The connector 70 and the corresponding cap 90 in the first opening 62 are fitted in the same manner as the connector 72 in the second opening 64.

  The pump head 2 is attached to the drive unit 1 as follows.

  Prior to use, for example after the tube 52 is assembled in the pump head 2, a lubricating oil, typically a liquid lubricating oil, is added to the pump chamber 16. Even though the amount of lubricating oil is sufficient to substantially cover the tube 52 and the pressing element 48, it does not fill the pump chamber 16. Valve 32 is closed by a piston 36 in sealing engagement with port 34, as shown in FIG. For this reason, the auxiliary chamber 18 is sealed from the pump chamber 16, thereby preventing the lubricating oil from leaking from the pump chamber 16 to the auxiliary chamber 18. For this reason, the pump head 2 can be transported and handled without the risk of lubricating oil leaking from the pump chamber 16 to the auxiliary chamber 18, that is, without risk of leakage from the pump head. As a result, the auxiliary chamber 18 is not wet before use.

  The pump head 2 is attached to the drive unit 1 in a substantially upright state such that the valve 32 is in the upper direction of the pump head 2. For this reason, the lubricating oil in the pump chamber 16 tends to accumulate away from the valve 32 at the bottom of the pump chamber 16.

  The drive unit 1 to which the pump head 2 is attached includes means for aligning with the pressing mechanism 40 of the pump head 2, and in this embodiment, the means is a protrusion 106 (shown in FIG. 6) from the drive unit 1. When the pump head 2 is attached, the pressing mechanism 40 is pressed and engaged with the protruding portion 106 so that the protruding portion 106 presses the pressing mechanism 40 into the recess 42 of the end cap 10. As shown in FIG. 6, the pushing mechanism 40 acts on the plunger 38 to move the piston 36 into a sealed and disengaged state with the port 34 and open the valve 32. Since the valve 32 is opened only when the pump head 2 is attached to the drive unit 1 and the pump head 2 is fixed in an upright state, the risk of the lubricating oil passing through the valve 32 and moving to the auxiliary chamber 18 is low.

  The drive unit 1 also includes an emitter 110 that emits infrared light and a receiver 112 that receives infrared light. The emitter 110 may be a light emitting diode and the receiver 112 may be a phototransistor. The emitter 110 and the receiver 112 are arranged such that when the pump head 2 is attached to the drive unit 1, the reflector 53 is arranged to reflect the infrared light emitted by the emitter 110 toward the receiver 112. 1 is arranged. The arrangement of the emitter 110 and the receiver 112 with respect to the reflector 53 is shown in FIG. In this embodiment, the emitter 110 and the receiver 112 are included in the same housing. The emitter 110, the receiver 112, and the reflector 53 together constitute an optical sensor that can detect the liquid in the auxiliary chamber 18. In the present embodiment, the reflector 53 is configured to exhibit substantially complete reflection on the inner surface of the infrared light emitted by the emitter 110 when there is no liquid on the outer surface of the cone portion. For this reason, when the pump head 2 is first attached to the drive unit 1, the receiver 112 detects the presence of reflected infrared light. A controller connected to the receiver 112 is used to check that the reflector 53 is not exposed to liquid, i.e., that the auxiliary chamber 18 is substantially free of liquid.

  The reflector 53 is a simple casting and is relatively inexpensive compared to the emitter 110 and the receiver 112. The advantage of the arrangement described above is that when the pump head 2 is worn or damaged, in particular when the tube 52 has reached its end of life, it is discarded as a unit and as a replacement pump head adapted to include a reflector. It is possible to do. The arrangement described above does not require replacement of the emitter 110 and the receiver 112 attached to the drive unit 1. As a result, the cost effectiveness of the pump head is greatly reduced compared to a pump head having an expensive sensor element attached to the pump head. Furthermore, the pump head 2 sealed by spin welding of the end caps 8 and 10 to the cylindrical housing 6 improves the integrity of the pump head 2 with respect to disposal.

  In use, the rotor 46 is rotated to press the tube 52 between the protrusion 50 of the pressing element 48 and the inner wall 12, thereby imparting a peristaltic action to the tube 52. The peristaltic action pumps the liquid through the tube 52. A part of the inner wall 12 that defines the annular passage 24 acts as a barrier between the pump chamber 16 and the valve 32. Thereby, the inner wall 12 prevents the lubricating oil splashed up by the pump operation from entering the auxiliary chamber 18 through the valve 32.

  In use, when the tube 52 ruptures or begins to leak in the pump chamber 16, the liquid pumped through the tube 52 leaks from the tube 52 to the pump chamber 16 and the passage 24. As the amount of leaked liquid increases, the liquid level in the pump chamber 16 becomes higher than the upper portion of the inner wall 16, and the liquid flows from the passage 24 into the auxiliary chamber 18 through the valve 32.

  The liquid that has flowed into the auxiliary chamber 18 is accumulated in a container portion around the snorkel 45. As the liquid accumulates in the container portion, the liquid level reaches the reflector 53, thereby exposing at least a portion of the outer surface of the cone portion of the reflector 53 to the liquid. Since the liquid has a higher refractive index than air, the amount of reflection at the inner surface played by the reflector 53 is reduced. As a result, the amount of infrared light reflected back toward the receiver 112 is reduced. The decrease in reflected radiation is detected by the controller and used to check that liquid is present in the container. An output, such as a warning, is issued to indicate that the tube has been broken (eg, ruptured) and a leak has occurred. At this time, the pump can be automatically stopped or stopped by the user in response to the output.

  As the water level increases until it exceeds the snorkel inlet, liquid is discharged from the auxiliary chamber 18 through the pipe 44.

  In this embodiment, the positioning recess 11 is formed so that the tube 52 extends in the horizontal direction from the pump head 2 (as shown in FIGS. 7 and 8) or in the state in which the pump head extends in the vertical direction. 1 so that it can be attached to one. The valve 32 is disposed inside the pump head 2 so that the valve 32 is disposed above the pump chamber 16 in each configuration. In addition, in each configuration, the pipe 44 has the tube 52 from the pump head 2 so that the snorkel 45 is 45 ° with respect to the vertical direction and the container portion is defined below the snorkel inlet 47 in each configuration. It arrange | positions in the direction of 45 degrees with respect to a substantial extending | stretching direction.

  Other types of optical sensors including suitable reflectors may be used. For example, an optical sensor may be arranged so that when the reflector is exposed to liquid, the amount of radiation reflected to the receiver side increases. The cone portion is described as a suitable shape that forms a reflective surface, but may be any surface, such as a pyramid or frustum shape, that changes the amount or direction of radiation reflected when exposed to liquid. It's okay. Alternatively or additionally, the reflector can be made of a suitable material and / or has a coating that varies the amount of radiation reflected depending on the degree to which the reflector is exposed to the liquid. Can be provided.

  The sensitivity of the receiver / controller can be adjusted to prevent leaks from being detected by a small amount of liquid.

  The optical sensor is also used to detect the presence or correct attachment of the pump head 2 in the drive unit 1 by detecting the presence of reflected radiation when the pump head 2 is attached to the drive unit 1. Can.

  A pump head 202 according to another embodiment of the pump head 2 described above is shown in FIG.

  The pump head 202 includes a housing 204 formed by a cylindrical case 206 that is closed at one end by an integral end wall 208 and at the other end by an end cap 210. In the present embodiment, the end cap 210 is ultrasonically staken in the case 206. The case 206 includes an outer wall 212 and an inner wall 214 disposed on the radially inner side of the outer wall 212. The outer wall 212 and the inner wall 214 are connected by a circumferential rib 216. The end wall 208 is formed integrally with the inner wall 214, for example, as a molded monocoque structure.

  The outer wall 212 extends to cover the inner wall 214 in the axial direction.

  A circular plate 218 is disposed inside the case 206. The circular plate 218 is arranged so that the periphery of the plate 218 is sealed against the inner surface of the outer wall 212. Further, the plate 218 is disposed adjacent to the end of the inner wall 214 so that the plate 218, the inner wall 214 and the end wall 208 define the pump chamber 220. The plate 218 includes an axially extending rib 222 that surrounds the outer surface of the inner wall 214 so as to support the inner wall 214.

  The pump head 202 further includes a rotor 223 that includes a pressing element 224 arranged to rotate within the pump chamber 220. The pressing element 224 includes a radially outer surface 226 that defines a protrusion 228 (shown in FIG. 10) for pressing a tube mounted inside the pump chamber 220 against the inner wall 214. The radially outer surface 226 is firmly connected to the core 230 of the rotor 223 by a lattice structure 232 that extends between the core 230 and the outer surface 226 of the pressing element 224. The rotor 223 is rotationally supported by a bearing 234 disposed between the outer surface 226 of the pressing element 224 and support mechanisms 236 and 238 provided on the end wall 208 and the plate 218, respectively.

  The core 230 extends through the plate 218 and the end cap 210. Seal members 240 and 242 are disposed between the core 230 and the plate 218 and between the core 230 and the end cap 210, respectively. The core 230 includes an axially extending splined bore 243 that is arranged to accommodate a drive shaft or similar drive means of the drive unit. The rotor 223 is disposed inside the pump head 202 so as not to protrude from the pump head housing 204.

  The plate 218, the outer wall 212, and the end cap 210 define an auxiliary chamber 244. The auxiliary chamber 244 is separated from the pump chamber 220 by a plate 218.

  As shown in FIG. 11, a plurality of leakage apertures 246 are provided in a part of the plate 218 adjacent to the pump chamber 220. There may be one leakage opening.

  The valve 248 is disposed between the leakage opening 246 and the auxiliary chamber 244.

  The valve 248 includes a first annular formation 250 formed on the side of the plate 218 exposed to the auxiliary chamber 244 and a stepped shape formed around the opening 254 provided in the end cap 210. And a second second annular formation 252. The first annular portion 250 and the second annular portion 252 define a second cylindrical portion 252 in the end of the first annular portion 250 so as to define a substantially cylindrical cavity 256 extending between the opening 254 and the plate 218. Are stretched together so that their stepped ends fit. A seal member 257 is disposed between the first annular portion 250 and the second annular portion 252 to seal the cavity 256 from the auxiliary chamber 244.

  The valve further includes a piston 258 disposed within the cavity 256. A first seal member 260 and a second seal member 262 are disposed at both ends of the piston 258. The seal member 260 and the seal member 262 seal the piston 258 inside the second annular portion 252. The piston 258 includes a constricted portion having a smaller diameter between the two seal members 260 and 262 as compared with both ends of the piston 258.

  In the vicinity of the constricted portion of the piston 258, an opening 264 that passes through a part of the second annular portion 252 between the seal member 260 and the seal member 262 and is separated in the circumferential direction is provided.

  The first seal member 260 seals the piston 258 against the second annular portion 252 to prevent fluid from leaking from the pump head through the opening 254 at the end cap 210. The second seal member 262 seals the end of the second annular portion 252 to prevent fluid from moving from the pump chamber 220 to the auxiliary chamber 244 via the valve 248. The second seal member 262 has a diameter larger than the inner diameter of the second annular portion 252.

  The piston 258 includes a pressing mechanism 264 such as a button at one end that is flush with the main portion of the end cap 210. A bore 266 extends along the piston 258 and within the bore 266 a biasing element in the form of a compression spring 268 is disposed. One end of the spring 268 is adjacent to the end of the bore 266 and the other end of the spring 268 is adjacent to the plate 218. Spring 268 urges piston 258 away from plate 218, thereby pressing second seal member 262 against the end of second annular portion 252 to close valve 248.

  As shown in FIG. 9, the auxiliary chamber 244 is provided with an outlet 270 on the opposite side of the valve 248 in the radial direction. The outlet 270 includes a pipe 272 that defines a snorkel 274 having an outlet 277 in the lower region of the auxiliary chamber 244. A container portion is defined around the snorkel 274 between the snorkel 274 and the wall of the annular chamber 244. The snorkel 274 is positioned so that the snorkel 274 is substantially vertical when the pump head 202 is in use. Other aspects of the outlet 270 are the same as those described with respect to the previously described embodiments and will not be described in detail here.

  The pump head 202 further includes a reflector 275 corresponding to the reflector described with respect to the previously described embodiments.

  A tube 276 is disposed inside the pump head 202 in a manner substantially similar to the embodiment described above. However, here the tube end fitting 278 is described with reference to FIG.

  Each tube end fitting 278 includes a first portion 282, a second portion 286, and a retaining element comprised of a cap 290. The first portion 282 and the second portion 286 are separated.

  Each of the first portions 282 is provided with a communication passage 294, a male thread shank 298, and an adjacent shoulder 302 that correspond to the same named mechanism as in the previous embodiment. The adjacent shoulder 302 includes a flange provided on the end surface 306 of the first portion 282. For example, a circumferential recess 310 is provided on an end surface 306 on which a seal member 314 such as an O-ring is disposed.

  Each of the first parts 282 is provided with a tool engagement mechanism 318, and the tool engagement mechanism 318 is a hexagonal socket formed at the end of the communication passage 294 in this embodiment.

  Each of the second portions 286 includes a plug 322 for connection to a hose, a corresponding communication passage 326, and an adjacent portion 330 having an end surface 334 of the second portion 286, and the adjacent portion 330 is the present embodiment. Then it is a flange. The end surface 334 of the second portion 286 presses the seal member 314 of the first portion in order to seal the communication passages 294 and 326 of the first portion 282 and the second portion 286 in fluid communication with each other.

  Each of the caps 290 corresponds to the cap of the above-described embodiment except that the cap 290 is provided with a female screw 338 that is screwed into the male screw 342 provided on the case 206. Thereby, each of the caps 290 does not require elasticity. Each of the caps 290 holds the first portions 282 and 286 of the tube end fitting 278 pressed together and engaged.

  The assembly and operation of the pump head 202 substantially corresponds to the assembly and operation of the pump head of the embodiment described above. However, the differences in assembly and operation will now be described.

  Similar to the previously described embodiment, each of the end fittings 278 are mated by engaging the screws of the screw shank 298 with the inner wall of the tube 276. To rotate the first portion 282 relative to the tube 276 to engage the tool engagement mechanism 318 and pull the tube 276 along the screw shank 298 toward the adjacent shoulder 302, for example, an Allen key (Allen key). ) Is used. Similar to that described with respect to the previous embodiments, when the end of tube 276 is securely positioned in place, second portion 286 of connector 278 causes each of communication passages 294 and 326 to fluidly communicate with each other. It arrange | positions facing the sealing member 314 so that it may seal in the state connected to. A cap 290 is then placed over the second portion 286 and a corresponding feature of the case 206 to secure the first portion 282 and the second portion 286 together to secure the connector 278 in place. Is rotated along the screw.

  Pump head 202 is secured to the drive unit by inserting a spline drive shaft or other suitable drive means of a drive unit (not shown) into spline bore 243 of rotor 223.

  As shown in FIG. 12, the operation of attaching the pump head 202 to the drive unit brings the pressing mechanism 264 into engagement with a protrusion (not shown) of the drive unit. The projecting portion presses the piston 258 inward with respect to the spring 268. The second seal member 262 lifts the end of the second annular portion 252 such that an annular gap 346 is formed between the piston 258 and the second annular portion 252. This opens the valve 248. Accordingly, the fluid flows from the pump chamber 220 through the leakage opening 246 and the annular gap 346 to the auxiliary chamber 244 through the opening 264 circumferentially separated along the constricted portion of the piston 258. Can do.

  By removing the pump head 202, the spring 268 presses the piston 258 outward so that the second seal member 262 seals the end of the second annular portion 252. The larger outer diameter of the seal member 262 ensures that the piston 258 is retained within the pump head 202. As a result, the pump chamber 220 is sealed again for transportation, storage, or disposal.

  In two embodiments, the welding or staking of the end caps 8, 10 and 210 to the outer walls 6 and 212 creates a sealed unit that cannot be disassembled without destroying the parts. As a result, when the life of pump heads 2 and 202, which would normally be reached due to failure of tubes 52 and 276, is reached, the pump head is discarded as a unit and replaced with a new unit.

  Other configurations for snorkels 45 and 274 can be used to define the container portion. For example, the outlet from the auxiliary chamber can be arranged so that the container portion is defined below the outlet from the auxiliary chamber at the lower part of the auxiliary chambers 18 and 244.

Claims (14)

A pump chamber in which a pressing element that gives a peristaltic action to a tube extending inside is disposed;
A peristaltic pump head including an auxiliary chamber which is a drying chamber in normal use,
The pump chamber and the auxiliary chamber are arranged in fluid communication so that liquid moved from the pump chamber due to leakage from the tube to the pump chamber flows from the pump chamber to the auxiliary chamber. Peristaltic pump head.   The auxiliary chamber is a valve operable between an open state in which liquid can flow from the pump chamber to the auxiliary chamber and a closed state in which liquid does not flow from the pump chamber to the auxiliary chamber. The pump head according to claim 1, wherein the pump head communicates with the pump chamber via a pipe.   The pump head according to claim 2, wherein the valve is configured such that when the pump head is connected to a drive unit that drives the pressing element, the drive unit engages the pump head to open the valve. .   4. The pump head according to claim 2, wherein the valve includes a port and a piston that engages the port so as to close the port.   The pump head according to any one of claims 2 to 4, wherein the valve includes a biasing element that biases the valve to the closed state.   The pump head according to claim 1, wherein a liquid detector that detects the presence of liquid in the auxiliary chamber is disposed.   The pump head according to claim 6, wherein the auxiliary chamber is provided with an outlet. The outlet includes a snorkel;
The snorkel is disposed so as to protrude upward in the auxiliary chamber so as to define a container for storing liquid below the inflow port of the snorkel when the pump head is attached to a drive unit that drives the pump head. And
The pump head of claim 7, wherein the fluid detector is arranged to detect the presence of liquid in the container. A peristaltic pump including the pump head according to any one of claims 1 to 8 and a drive unit,
The pump head is a peristaltic pump configured to be detachable from the drive unit. A pump according to claim 9 when dependent on claim 2,
The pump head includes a plunger that drives a valve exposed to the outside of the pump head,
The drive unit has a protrusion that cooperates with the plunger to open the valve when the pump head is attached to the drive unit. A substantially cylindrical outer wall;
A peristaltic pump head including a pump head housing having at least one end cap permanently fixed to the outer wall.   The pump head of claim 11, wherein the end cap is spin welded or ultrasonically staked to the outer wall to form a sealed pump head housing.   The pump head according to claim 12, wherein the outer wall that is spin welded or ultrasonically stake to the end cap comprises a mold structure.   A peristaltic pump head or peristaltic pump substantially as herein described with reference to the accompanying drawings.